The present disclosure relates to a word line driving circuit and a semiconductor device using the same, and more particularly to a word line driving circuit which is not influenced by a ground voltage rising in a sensing operation and a semiconductor device using the same.
In general, a semiconductor memory performs, as basic operations thereof, a write operation of storing external input data therein and a read operation of reading data stored therein.
If a drive voltage is applied to a word line selected by an address decoded through a row decoder, then a cell transistor is turned on. Data stored in a capacitor is transferred to a bit line BL through the turned-on cell transistor, amplified by a sensing operation of a bit line sense amplifier (BLSA) and then outputted through a data input/output terminal DQ. This is called a read operation. Conversely, data inputted through the data input/output terminal DQ is transferred through the cell transistor turned on by the word line selection and then stored in the capacitor, which is called a write operation.
In order to perform the read and write operations, it is necessary to turn on the cell transistor. At this time, the word line drive voltage turning on the cell transistor must have a level sufficiently higher than a high level of data stored in a cell, for example, a high voltage (VPP) level, to enable storing data in the capacitor or reading data stored therein.
The sensing operation of the BLSA is performed after the cell transistor is turned on due to the application of a high voltage to the word line. This sensing operation involves a large amount of power consumption, which means that a large amount of current flows to a ground voltage VSS connected to the BLSA. As a result, during the sensing operation, the ground voltage VSS rises to a certain level, as shown in FIG. 1.
In a conventional dynamic random access memory (DRAM), however, both circuits for the sensing operation and circuits for word line driving employ the same ground voltage VSS as a turn-off voltage of the cell transistor. For this reason, a word line driving circuit and a semiconductor device using the same are also influenced by the ground voltage VSS rising in the sensing operation as it is. Consequently, leakage current in the cell transistor increases, resulting in a reduction in data retention time and, in turn, an increase in the possibility of errors occurring in memory operation.